Question: The arithmetic sequence $(a_i)$ is defined by the formula: $a_i = -5 + 4(i - 1)$ What is $a_{19}$, the nineteenth term in the sequence?
Solution: From the given formula, we can see that the first term of the sequence is $-5$ and the common difference is $4$ To find $a_{19}$ , we can simply substitute $i = 19$ into the given formula. Therefore, the nineteenth term is equal to $a_{19} = -5 + 4 (19 - 1) = 67$.